MINERAL WATERS. 



379 



Mineral water. At this time carbonic acid, an ingredient so 

 Wsiw*. common in mineral waters, and which is the agent by 

 "^"Y"^^ which many of the other substances are rendered solu- 

 ble, was not known. After the discovery of this gase- 

 ous fluid by Dr. BLACK, the labours of chemists were di- 

 rected to mineral waters, more particularly after the 

 publication of the essay of BERGMAN in 1778. Since 

 then, numerous mineral waters have been subjected to 

 analysis, by BLACK, KLAPROTH, WESTRUMB, FOUR- 

 t ROY, and others ; the result of whose labours, and the 

 different methods of analysis used by them, were pub- 

 lished in the works of KIRWAN and SATNDEKS, in 1800. 

 Of late, Dr. MI-RKAY has brought forward a new view 

 of the composition of these fluids, which threatens too ver- 

 turn the results of the experiments of former chemists, 

 and which has induced him to propose a method of 

 analysis, more simple than those generally follow. 

 ed. 



The examination of mineral waters, is perhaps one of 

 the most difficult pursuits of the chemist. It requires 

 an intimate knowledge of the action of bodies on each 

 other, and the utmost nicety in the manipulation ; the 

 quantity of matter on which he has to operate being so 

 minute. In the analysis of these fluids, the various 

 processes recommended, should be tried and compared, 

 and, if necessary, repeated till they agree in their re- 

 suits. 



The examination of a mineral water may be divided 

 into two parts ; 1st, The investigation of the physical 

 qualities of the water, with an account of the surround- 

 ing objects ; 2d, The chemical analysis of the fluid, so 

 as to ascertain its component parts. 



Of the Physical Qualities of the Water, fa. 



or the |.hy Before proceeding to the chemical investigation of a 



; .'::i- mineral water, it is necessary to ascertain the source from 



- which it is derived, the nature of the substances over 



irr , *c. wn j c h it has passed, and of the soil where it has its exit. 

 We must likewise attend to any matter which may be 

 deposited from it Its taste, odour, colour, and tempera- 

 ture, roust be observed, and the quantity of it dischar- 

 ged in a given time, and the rapidity with which it 

 flows must likewise be noticed. This examination of 

 the water ought to be performed at different times of 

 the day, and in different seasons, joth before and after 

 rain, as the quantity of the fluid discharged, and of 

 course its properties, vary according to the state of 

 the weather. By the knowledge thus acquired, some 

 information may be gained with respect to the nature 

 of the water, and of the substances which are contained 

 in it ; thus the odour and the taste point out whether 

 it be sulphureous or contain iron, and its sparkling indi- 

 cates the presence of an a.-rial fluid. 



Having made these observation*, the next step is to 

 proceed to the chemical investigation of the fluid. 



Of the Substamcet found in Mineral Hater*. 



Of !he tub- The substance* found in mineral waters may be di- 

 Min Tided into the gaseous fluids, the acid*, the alkalies, the 

 A in earths, and the compound salt*. 



1. Atmospheric air is contained in almost all mineral 

 watcr, UK- quantity however is not great, a* it Him 

 exceeds the ,',th of the volume of the water. It was 

 first pointed out in those fluids by Mr. Boyle. 



2. Oiyfen gat was found in mineral waters by Scheele. 

 It exists in small quantity, and is never contained in 



the tame water with sulphuretted hydrogen or the com- 

 pound* of iron. 



S. Xitrogen gas was detected in the Bath waters by Mineral 

 Dr. Priestley, in Buxton waters by Dr. Pearson, in w ai- 

 those of Harrowgate by Dr. Garnet, and in thoje of """Y"' 

 Lemington Priors, by Dr. Lambe. 



4. Carbonic acid is a very common ingredient in mi- 

 neral waters ; it was first discovered by Dr. Brownrigg 

 in those of Pyrraont. Its quantity varies considerably, 

 though in general it seldom exceeds that of the wa- 

 ter. According to Higgins, however, 100 cubic inch- 

 es of Pyrmont water contain IfiO, and, according to 

 \Vi-trumb, no less than 187 cubic inches of carbonic 

 acid. 



5. Boracic acid has been found in some of the lakes 

 of Italy, though in the waters in which it has been ob- 

 served, it in general exists in a state of combination. 



6. Sulphureous acid has been detected in some of the 

 waters of Italy near volcanoes. 



7. Sulphuretted hydrogen is a very common ingre- 

 dient in mineral waters. It was first discovered in diem 

 by Scheele. 



8. Soda is the only alkali which has been found, in 

 its free state, 'in mineral waters. According to Dr. 

 Black it exists in the waters of Geyser and II vkum, in 

 Iceland. 



9- iJmt also in its pure state, i* said by some che- 

 mists to exist in mineral waters. 



10. Silica exists in the waters of Geyser and in many 

 others. It was generally supposed that the earth was 

 held in solution by soda ; this however does not seem 

 to be the case, a* the quantity of alkali in the \\ aters 

 containing silica is so trifling. 



Nitric, carbonic, sulphuric, and muriatic acids, and 

 sulphuretted hydrogen, are frequently found in inine- 

 ral waters in union with potassa and soda, with lime 

 and magnesia, and with the oxide of iron. Baryta, alu- 

 mina, and the oxide of copper, have also been found in 

 con i hi nation with some of the alxjvr-nientioned acids, 

 though less frequently than the other bases. Sub- 

 borate of soda has likewise been detected in the lake* 

 of Thibet and Persia ; these waters, however, do not be* 

 long to those properly called mineral waters. 



The nitrates uc rarely found in mineral waters. 



11. Nitrate of' potassa has been detected in some of 

 those in Hungary and in the salt springs in Germany. 



1. Nitrate of lime was first discovered to exist in 

 water by Dr. Home. It is found also in some springs 

 in the Detcrt* of Arabia. 



The ca:bi. nates are perhap* the most frequent of the 

 compound salts contained in mineral waters. 



1 :'>. Carbonate of potassa has sometimes, though rare, 

 ly, been found. When present it is in small qu u:ti- 



t.v- 



14. Carbonate of soda is a much more abundant pro- 

 duction, being contained in a great many waters. 



15. Carbonate of ammonia is seldom deteited. 



16. Carbonate of lime, in union with an excess of car- 

 bonic, is perhaps the most common ingredient in mineral 

 waters, few waters existing without it. 1000 parts of 

 water by weight, when they contain 2 of carbonic acid, 

 can dissolve t of carbonate of lime. As the quantity of 

 water increases, the carbonic acid necessary to held the 

 carbonate of lime in solution, becomes smaller. What- 

 ever be the quantity of carbonic acid in water, it is 

 able to hold the carbonate of lime in solution, provided 

 the carbonic acid exceed the weight of the lime. 



17. Carbonate of' magnesia is frequently found in 

 mineral waters, also held in solution by an excess of 



